1. Field of the Invention
The present invention relates to communication networks, and, more particularly, to accounting for a user's bandwidth needs as a user moves through a wireless communication network.
2. Description of the Related Art
A wireless telecommunication network includes a group of base stations that support multiple portable (“mobile”) and fixed transceivers. For convenience, each transceiver is commonly termed a “unit.” Each base station supports a number of logical connections with units within the base station's coverage area, sometimes referred to as a “cell.” These logical connections may be through one or more physical connections transferring modulated and encoded data between each unit and the base station according to any number of communication techniques known in the art. Logical and physical connections are typically characterized by their available capacity for carrying data, expressed in bandwidth or data rate. For example, a logical connection of 64 kbps capacity may be implemented using two physical connections, each of 32 kbps capacity. Although a unit connection may be established with other units within the cell or wireless network, typically the unit's logical connection accesses an external network. External networks are generally land-based telecommunication systems, such as the POTS (plain old telephone service) network, dedicated data networks, and/or the Internet.
While a unit may send a request to the base station to establish a logical connection, generally the base station coordinates and controls the process of setting-up the portion of the connection between the base station and the unit. Base stations themselves may be linked to a call management system that coordinates actions of the base stations in the network. The call management system is typically responsible for establishing the portion of the connection from the base station to the external network. At a given point in time, each base station is supporting a different number of units within its coverage area, and the base stations may have different available bandwidth or services depending on their provisioning and equipment configuration.
When traveling through the wireless network, the unit shifts communication between base stations offering network access along the route taken by the unit. Shifting of communication between base stations, commonly known as “handoff,” includes the process of maintaining a logical connection with one base station while negotiating a new logical connection with another base station. Generally, a unit may have several candidate base stations to select from when starting the process of setting up the new logical connection. Prior art networks generally employ a metric, such as signal-to-noise ratio and/or number of units currently served by the base station, during the negotiation process to select the base station for the new logical connection.
As popularity of wireless networks grows, such networks are increasingly pressured to offer greater capacity in logical connections to support relatively large file transfer, such as generated by Internet access, data-networking, and other types of wireless computer networking applications. However, since effects of handoff between base stations should be transparent to the logical connection, a connection with a large file transfer between a unit and one base station may have adequate capacity, but such capacity may not be available in the new connection after handoff of the connection to another base station. Without sufficient capacity, generally the data application coordinating the file transfer will “throttle-back” the connection, transferring data at a slower rate.
Recently many transceivers, such as units in a wireless network, are incorporating features that allow the transceiver to detect its position on the Earth. While many systems exist, such as LORAN and VOR in aircraft, by far the most widespread system in use is the Global Positioning System (GPS). GPS employs a group of satellites in geo-synchronous orbit, each satellite transmitting it's identification (ID) signal and a timing signal locked to a standard reference. A transceiver searches the sky for ID signals from at least three satellites of the GPS system. When three or more different ID signals are acquired, the corresponding timing signals are compared. The phase differences between timing signals represent delays caused by the different distances between the transceiver and each acquired satellite. With a priori information known through identification of each satellite, triangulation may be used to determine the transceiver's position on the Earth.